JP5492809B2 - Fixing member, manufacturing method thereof, fixing device, and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing member obtained by coating a fluororesin film on the outer surface of a silicone rubber layer formed on the surface of a core material, a manufacturing method thereof, a fixing device including the fixing member, and an image forming apparatus including the fixing device. Is.

  In an image forming apparatus such as a copying machine or a printer that forms an image on a recording material such as paper by an electrophotographic method, a toner is developed by developing an electrostatic latent image formed on an image carrier such as a photosensitive drum by a developing device. An image is visualized and the toner image is transferred onto a recording material. Then, the recording material onto which the toner image has been transferred is conveyed to a fixing device, heated and pressurized by the fixing device, and after being fixed on the toner image, it is discharged out of the apparatus, thereby performing a series of image forming operations. Is completed.

  By the way, as a fixing method of the fixing device in such an image forming apparatus, a heating roller method and a fixing belt method are conventionally known. Here, a fixing device that employs a heating roller system will be described as an example.

  That is, a fixing device that employs a heating roller method as a fixing method includes a fixing roller and a pressure roller that rotate in contact with each other, and a fixing heater is disposed inside the cylindrical fixing roller. The pressure roller is formed by forming a silicone rubber layer on the outer surface of the cored bar and coating the outer surface with a fluororesin film (PFA tube or the like) as a release layer.

  Incidentally, in recent years, volatile organic compounds (VOC) generated from electronic devices have been regulated by various environmental standards, and volatile organic compounds (VOC) generated from image forming apparatuses are generated from fixing devices. Siloxane accounts for a large percentage. Most of the siloxane generation sources are those generated from silicone rubber contained in the fixing roller and pressure roller. In order to comply with environmental standards, how to reduce the amount of siloxane generated from this silicone rubber? Has become an issue. Also, if the surface of electrical circuits or relay contacts is contaminated by this siloxane, problems such as contact failure will occur, and if siloxane adheres to the mirror of the optical system, the optical performance will deteriorate. Therefore, reducing the amount of siloxane is a major challenge.

  Therefore, in Patent Document 1, a cap member that is opposed to both ends of the silicone rubber layer included in the sheet conveying roller via a gap is provided on the core metal, and at least an outer periphery of the cap member is covered with a resin tube, and the gap is formed. The structure which seals is proposed.

  Further, Patent Document 2 proposes a configuration in which an adsorbent that adsorbs a volatile organic compound is provided on a core metal located at both ends of a silicone rubber layer included in a sheet conveying roller.

JP 2008-009264 A JP 2008-009265 A

  However, according to the configuration proposed in Patent Document 1, since the cap member is newly required and the number of parts is increased, and the cap member is disposed through the gap, the groove is formed in the resin tube in the gap portion. If the cap member is located in the nip with the opposing roller, the cap member may be damaged by repeated rotation and stop of the sheet conveying roller. There is. In order to avoid this, if the cap member is disposed outside the nip with the counter roller, there arises a problem that the fixing device becomes large. Furthermore, the cap member needs to have a thickness of 5 mm or more because it is necessary to suppress vibration due to rotation by itself, and this also causes a problem that the fixing device becomes large.

  Moreover, even if it is the structure proposed in patent document 2, since the condition where the adsorption body is covered with the resin tube is the same as patent document 1, the same problem as the above will generate | occur | produce.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the object of the present invention is a fixing member that can prevent the volatile organic compound siloxane from being diffused, a manufacturing method thereof, and a fixing device that can be miniaturized. And providing an image forming apparatus including the same.

  In order to achieve the above object, a first aspect of the present invention provides a fixing member in which a silicone rubber layer is formed on a core material and a fluororesin film is coated on the outer surface of the silicone rubber layer. An end face portion that is not covered with the fluororesin film and is exposed to the outside is made of silicone rubber having a lower volatile component content and higher hardness than other portions.

  The invention according to claim 2 is the invention according to claim 1, wherein the volatile component content (volatile component extraction amount) of the silicone rubber constituting the end surface portion of the silicone rubber layer is 10 μg / ml or less, and the hardness is 20 or more. It is characterized by setting.

  The invention according to claim 3 is a method of manufacturing a fixing member in which a silicone rubber layer is formed on a core material and a fluororesin film is coated on the outer surface of the silicone rubber layer, and the content of volatile components and the hardness thereof are Two different types of silicone rubber are prepared, and the volatile component content is low in the space between the core material and the fluororesin film of the vertical mold in which the core material and the fluororesin film are inserted and set in advance. The liquid silicone rubber with higher hardness is poured into the specified height, and the liquid silicone rubber with higher volatile component content and lower hardness is poured into the specified height, and further contains the volatile component. The liquid silicone rubber having a lower amount and higher hardness is poured into a predetermined height, and then vulcanized while maintaining the state.

  According to a fourth aspect of the present invention, there is provided a fixing device including the fixing member according to the first or second aspect or the fixing member manufactured by the manufacturing method according to the third aspect.

  The invention according to claim 5 is the invention according to claim 4, the invention according to claim 2 is the invention according to claim 1, and the end surface portion of the silicone rubber layer included in the fixing member is outside the image area. It is arranged.

  The invention according to claim 6 is the invention according to claim 4 or 5, and the invention according to claim 2 is the invention according to claim 1, wherein the outer diameter of the end surface portion of the silicone rubber layer included in the fixing member is determined. Alternatively, the thickness is set to be smaller than the outer diameter or thickness of the central portion.

  An image forming apparatus according to a seventh aspect includes the fixing device according to any one of the fourth to sixth aspects.

  According to the first aspect of the present invention, the end surface portion that is not covered with the fluororesin film of the silicone rubber layer and is exposed to the outside, that is, the end surface portion in which siloxane, which is a volatile organic compound, has conventionally diffused, is replaced with another portion. Since it is made of silicone rubber having a lower volatile component content and higher hardness, the siloxane emission from the end face of the silicone rubber layer is suppressed. In addition, since the hardness of the portion excluding the end face portion of the silicone rubber layer is kept lower than the hardness of the end face portion, an appropriate fixing nip can be secured by the fixing member. Furthermore, since the end surface portion of the silicone rubber layer is integrated with other portions, the two are not separated even after long-term use, and the durability of the fixing member is improved.

  According to the second aspect of the present invention, by setting the volatile component content (volatile component extraction amount) of the silicone rubber constituting the end surface portion of the silicone rubber layer to 10 μg / ml or less and the hardness to 20 or more, the fixing member While suppressing the diffusion of siloxane to the outside, it is possible to increase the durability of the fixing member by preventing the performance and strength of the silicone rubber as an elastic body from decreasing. Incidentally, the volatile component content and the hardness of the silicone rubber are inversely proportional, and if the volatile component content (volatile component extraction amount) of the silicone rubber exceeds 10 μg / ml, the siloxane is released from the fixing member. If the hardness of the silicone rubber is kept at less than 20, the suppression effect cannot be expected, and the volatile component content (volatile component extraction amount) exceeds 10 μg / ml, so that it is impossible to suppress the diffusion of siloxane out of the fixing member.

  According to the invention described in claim 3, the space between the core material of the vertical mold in which the core material and the fluororesin film are inserted and set in advance and the fluororesin film have a low volatile component content and a high hardness. The liquid silicone rubber with the higher volatile component content and lower hardness, and the liquid silicone rubber with the lower volatile component content and higher hardness are poured in order, and the state is maintained. By vulcanization, it is possible to produce a fixing member capable of preventing the siloxane from being released to the outside with high productivity.

  According to a fourth aspect of the present invention, the fixing member provided in the fixing device is structurally configured so that the volatile component content and hardness of the silicone rubber constituting the end surface portion exposed to the outside of the silicone rubber layer are the other portions. However, since the shape and dimensions of the fixing member are not changed, the cap member and the adsorbing member for preventing the siloxane from being released to the outside are newly provided on the end face of the silicone rubber layer. Thus, the overall length does not become long and the fixing device can be downsized.

  According to the fifth aspect of the present invention, the end surface portion of the silicone rubber layer of the fixing member whose apparent hardness is higher than the other portion (image region portion) due to low volatile component content is disposed outside the image region. Therefore, an appropriate fixing nip is formed by the fixing member in the image area, and the toner image is well fixed on the recording material.

  According to the sixth aspect of the present invention, the outer diameter or thickness of the end face portion of the silicone rubber layer whose apparent hardness is higher than other portions due to low volatile component content is the same as the outer diameter or thickness of the central portion. Therefore, the pressure per unit area in the fixing nip formed by the fixing member is made uniform in the longitudinal direction, so that the toner image can be well fixed on the recording material.

  According to the seventh aspect of the invention, since siloxane is prevented from being diffused from the fixing device, it is possible to ensure high fixability and stably obtain a high quality image while preventing deterioration of the environment.

1 is a cross-sectional view of an image forming apparatus according to the present invention. FIG. 3 is a cross-sectional view of a main part of the fixing device according to the present invention. It is a cross-sectional view of the pressure roller according to the present invention. (a)-(d) is sectional drawing which shows the manufacturing method of the pressure roller which concerns on this invention in the order of the process. FIG. 3 is a side view of a fixing belt according to the present invention. It is the sectional view on the AA line of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Image forming apparatus]
FIG. 1 is a cross-sectional view of an image forming apparatus according to the present invention. The illustrated image forming apparatus 1 is a laser printer, and an image forming unit 2 is disposed above the inside of the apparatus main body 1A. A sheet storage unit 3 is disposed in the lower half of the sheet.

  The image forming unit 2 forms an image by an electrophotographic method. The image forming unit 2 is a photosensitive drum 4 as a rotatable image carrier, a charger 5 disposed around the photosensitive drum 4, a developing device 6, and the like. In addition to the transfer roller 7 and the cleaning device 8, the developing device 6 is provided with a toner hopper 9 for supplying toner as a developer. A laser scanner unit (LSU) 10 that is an optical scanning device is disposed beside the image forming unit 2.

The paper storage unit 3 includes detachable upper and lower two-stage paper feed cassettes 11 and 12 in which a plurality of paper sheets as recording materials are stacked and accommodated, and in the vicinity of each of the paper feed cassettes 11 and 12, A pick roller 13 for sequentially taking out the paper in each of the paper feed cassettes 11 and 12 from the upper one, a feed roller 14 for feeding out the taken paper one by one and a retard roller 15 are provided. In the apparatus main body 1A, a first transport path S1 from the paper storage unit 3 to the image forming unit 2 and a second transport path S2 from the image forming unit 2 to the paper discharge tray 16 are disposed. The registration roller 17 and the transfer roller 7 are provided in the path S1, and the fixing device 18, the conveyance roller 19, and the paper discharge roller 20 according to the present invention are provided in the second conveyance path S2. Details of the configuration of the fixing device 18 will be described later.

  Next, an image forming operation of the image forming apparatus 1 configured as described above will be described.

  When the image forming operation is started, in the image forming unit 2, the photosensitive drum 4 is rotationally driven in a direction indicated by an arrow (clockwise) in FIG. Uniformly charged. When a laser beam based on an electrical signal transmitted from a personal computer or the like is output from the laser scanner unit 10 and the surface of the photosensitive drum 4 is exposed and scanned, an electrostatic latent image corresponding to image information is formed on the photosensitive drum 4. Is formed. The electrostatic latent image formed on the photosensitive drum 4 is developed by the developing device 6 using toner as a developer to be visualized as a toner image.

  By the way, when cassette feeding is performed, the paper stored in, for example, the upper paper feeding cassette 11 of the paper storage unit 3 is picked up from the uppermost one by the pick roller 13 and is fed by the feed roller 14 and the retard roller 15. The sheets are separated one by one and conveyed to the registration roller 17 through the first conveyance path S1. In the registration roller 17, after the paper is temporarily in a standby state, the paper is supplied to the image forming unit 2 at a predetermined timing synchronized with the toner image on the photosensitive drum 4.

  In the image forming unit 2, the sheet supplied to the nip between the photosensitive drum 4 and the transfer roller 7 is conveyed while being pressed against the photosensitive drum 4 by the transfer roller 7, so that the surface of the photosensitive drum 4 is conveyed. The upper toner image is transferred. Then, the sheet on which the toner image is transferred is conveyed to the fixing device 18 and is heated and pressurized in the process of passing through the nip of the fixing device 18 to receive the fixing of the toner image. The toner remaining on the surface of the photosensitive drum 4 (transfer residual toner) after the transfer of the toner image onto the paper is removed by the cleaning device 8, and the photosensitive drum 4 whose surface has been cleaned is prepared for the next image forming operation.

  Thus, the sheet on which the toner image is fixed on the surface by the fixing device 18 is conveyed toward the sheet discharge roller 20 by the conveyance roller 19 through the second conveyance path S2, and to the sheet discharge tray 16 by the sheet discharge roller 20. This completes a series of image forming operations.

[Fixing device]
Next, the fixing device 18 according to the present invention will be described below with reference to FIGS.

  2 is a cross-sectional view of the main part of the fixing device according to the present invention, FIG. 3 is a transverse cross-sectional view of the pressure roller of the identification fixing device, and the fixing device 18 shown in the figure adopts a heating roller method as a fixing method. In addition, a fixing roller 21 and a pressure roller 22 that are in contact with each other and rotate in the direction indicated by the arrow are provided. A fixing heater 23 is disposed inside the cylindrical fixing roller 21. A pressure roller 22 is pressed against the fixing roller 21 from below to form a predetermined fixing nip with the fixing roller 21.

  In the present embodiment, the fixing roller 21 is configured by coating the outer surface of an aluminum cored bar 24 with a fluororesin 25 such as PFA or PTFE filled with a conductive material or wear-resistant material. The fixing heater 23 disposed inside the fixing roller 21 is composed of a halogen lamp, and the fixing roller 21 is heated to a predetermined fixing temperature by the fixing heater 23. The surface temperature of the fixing roller 21 is always detected by a temperature sensor (not shown), and the detection signal is fed back to a controller (not shown) to control the surface temperature of the fixing roller 21 to a predetermined fixing temperature.

  The pressure roller 22 has a cylindrical silicone rubber layer 27 formed on the outer surface of a metal core 26 made of stainless steel or the like, and a PFA, PTFE, or the like as a release layer on the outer surface of the silicone rubber layer 27. The fluororesin film 28 is covered.

  Thus, in the present embodiment, as shown in FIG. 3, the longitudinal direction (paper passing width direction) exposed to the outside without being covered with the fluororesin film 28 of the silicone rubber layer 27 provided on the pressure roller 22. The end face portions (width b portions) 27A at both ends are made of silicone rubber having a lower volatile component content and higher hardness than the other portions. Specifically, the volatile component content of the silicone rubber constituting the end surface portion 27A of the silicone rubber layer 27 (the volatile component extraction amount is set to 10 μg / ml or less, and the hardness is set to 20 or more.

  Further, in the fixing device 18 according to the present embodiment, the end surface portion 27A of the silicone rubber layer 27 included in the pressure roller 22 is disposed outside the image region (non-image region), and the end surface portion 27A of the end surface portion 27A. The outer diameter φD1 is set smaller than the outer diameter φD2 at the center (φD1 <φD2).

  Here, the manufacturing method of the pressure roller 22 comprised as mentioned above is demonstrated below according to Fig.4 (a)-(d). 4A to 4D are cross-sectional views showing the method of manufacturing the pressure roller according to the present invention in the order of steps.

  A vertical mold 30 is used for the production of the pressure roller 22, and the mold 30 is formed by vertically standing a cylindrical mold 31 having an inner diameter that is the same as the outer diameter of the pressure roller 22. The upper mold 32 and the lower mold 33 are respectively fitted on the upper and lower sides of the cylindrical mold 31.

  Thus, when the pressure roller 22 is manufactured, two types of silicone rubbers having different volatile component contents and hardness are prepared. First, as shown in FIG. 26 is inserted and set vertically, and a cylindrical fluororesin film (PFA tube) 28 is inserted and set along the inner surface of the cylindrical mold 31. Next, as shown in FIG. 4B, the liquid silicone rubber 27a having a lower volatile component content and higher hardness is inserted into the core in the mold 30 from the injection port 32a formed at the center of the upper mold 32. Pour the height b into the space between the gold 26 and the fluororesin film 28, and then, as shown in FIG. Pour only for minutes. Finally, as shown in FIG. 4D, the liquid silicone rubber 27a having a lower volatile component content and higher hardness is poured onto the liquid silicone rubber 27b having a higher volatile component content and lower hardness. If the state is vulcanized, the left and right end portions 27A of the silicone rubber layer 27 as shown in FIG. 3 in which the silicone rubbers 27a and 27b, the silicone rubbers 27a and 27b, the core metal 26, and the fluororesin film 28 are integrated. However, the pressure roller 22 made of silicone rubber having a low volatile component content and a high hardness relative to other parts is manufactured.

  According to the manufacturing method of the pressure roller 22 described above, a volatile component is formed in the space between the core metal 26 and the fluororesin film 28 of the vertical mold 30 in which the core metal 26 and the fluororesin film 28 are inserted and set in advance. Liquid silicone rubber 27a having a lower content and higher hardness, liquid silicone rubber 27b having a higher volatile component content and lower hardness, and liquid silicone rubber 27a having a lower volatile component content and higher hardness After pouring, the pressure roller 22 composed of silicone rubber having a low volatile component content and high hardness is produced in the left and right end face portions 27A of the silicone rubber layer 27 by vulcanizing while maintaining the state. Can be manufactured well.

  Thus, in the pressure roller 22 used in the fixing device 18 according to the present embodiment, the end surface portion 27A exposed to the outside without being covered with the fluororesin film 28 of the silicone rubber layer 27, that is, in the past, is volatilized. Since the end face portion 27A from which the siloxane, which is a volatile organic compound, has been diffused is made of silicone rubber having a lower volatile component content and higher hardness than other portions, the siloxane emission from the end face of the silicone rubber layer 27 is suppressed. The Further, since the hardness of the silicone rubber layer 27 other than the end surface portion 27A is suppressed to be lower than the hardness of the end surface portion, the fixing roller 21 and the pressure roller 22 can ensure an appropriate fixing nip. Furthermore, since the end surface portion 27A of the silicone rubber layer 27 is integrated with other portions, they are not separated even after long-term use, and the durability of the pressure roller 22 is enhanced.

  By the way, the volatile component content and the hardness of the silicone rubber are inversely proportional to each other. If the volatile component content (volatile component extraction amount) of the silicone rubber exceeds 10 μg / ml, the emission of siloxane to the outside of the fixing member is suppressed. The effect cannot be expected, and if the hardness of the silicone rubber is kept at less than 20, the volatile component content (volatile component extraction amount) exceeds 10 μg / ml, and it becomes impossible to suppress the diffusion of siloxane to the outside of the pressure roller 22. .

  In the present embodiment, the volatile component content (volatile component extraction amount) of the silicone rubber constituting the end surface portion 27A of the silicone rubber layer 27 is set to 10 μg / ml or less and the hardness is set to 20 or more. It is possible to improve the durability of the pressure roller 22 by preventing the performance and strength of the silicone rubber as an elastic body while suppressing the diffusion of the siloxane.

  The pressure roller 22, structurally, only changes the volatile component content and hardness of the silicone rubber constituting the end face portion 27A exposed to the outside of the silicone rubber layer 27 with respect to those of other portions, Since there is no change in its shape and dimensions, the total length does not become longer like a pressure roller newly provided on the end face of the silicone rubber layer with a cap member and adsorption member for preventing siloxane from being released to the outside, As a result, the fixing device 18 can be downsized.

  Furthermore, in the fixing device 18 according to the present embodiment, the end surface of the silicone rubber layer 27 of the pressure roller 22 whose apparent hardness is higher than other portions (image region portions) due to low volatile component content. Since the portion 27A is arranged outside the image area (non-image area), an appropriate fixing nip is formed by the fixing roller 21 and the pressure roller 22 in the image area, and the toner image is well fixed to the gist.

  Further, in the present embodiment, the outer diameter φD1 of the end surface portion 27A of the silicone rubber layer 27 whose apparent hardness is higher than other portions due to the low content of volatile components is smaller than the outer diameter φD2 of the center portion. Since it is set (φD1 <φD2), the pressure per unit area in the fixing nip formed by the fixing roller 21 and the pressure roller 22 is made uniform in the longitudinal direction, and the toner image is well fixed on the paper.

  Next, examples of the present invention will be described below together with comparative examples.

  In this example, the amount of siloxane generated in a pressure roller having a volatile component content (volatile component extraction amount) of 10 μg / ml and a hardness of 20 at the end face of the silicone rubber layer was measured, and the results are shown in Table 1. Shown as an example. Further, as a comparative example, the combinations of the volatile component content (volatile component extraction amount) and the hardness of the end face portion of the silicone rubber layer and the hardness are (10 μg / ml, 15), (19 μg / ml, 20), (40 μg / ml, 15 ) Were also measured, and the results are shown in Table 1 as Comparative Examples 1, 2, and 3, respectively.

  The content of volatile components (extracted amount of volatile components) was divided into 32 parts of 10 mg of silicone rubber, immersed in 10 ml of THF solution, and allowed to stand at a temperature of 25 ° C. for 12 hours. It measured by measuring 1 microliter, applying to GC-MS apparatus, and quantifying the cyclohexane type | system | group volatile component detected during the retention time in which cyclodecane is detected from cyclohexane in conversion of toluene. The hardness was measured using a JIS-A hardness meter in accordance with JISK-6301.

The amount of siloxane generated is measured by installing each pressure roller in the fixing device of a modified KM-C3232 machine manufactured by Kyocera Mita Co., Ltd., and installing the modified machine in a chamber made of SUS with a volume of 5 m ³ and an air volume of 15 m ³ / Ventilation was performed at h. Then, after ventilation for about 1 hour, printing was performed for 10 minutes, and volatile substances generated from the inside of the apparatus were sampled by an amount of 100 ml / min with a Tenax tube. After that, sampling was continuously performed for about 20 minutes even after printing was stopped. Then, the sampled Tenax tube was desorbed with a heat desorption apparatus, and measurement was performed with GC-MS to calculate the amount of siloxane gas generated.

表１に示す結果から明らかなように、シリコーンゴム層の端面部分の揮発成分含有量（揮発成分抽出量）が１０ｍｇ／ｍ^３、硬度が２０に設定された実施例ではシロキサン発生量を３５μｇ／ｍ３と低く抑えられたのに対して、揮発成分含有量（揮発成分抽出量）と硬度が実施例の範囲を超える比較例１〜３ではシロキサン発生量がそれぞれ２１０ｇ／ｍ^３、１１８ｇ／ｍ３．２０１ｇ／ｍ^３と高い値を示す。

As is clear from the results shown in Table 1, in the example in which the volatile component content (volatile component extraction amount) at the end surface portion of the silicone rubber layer was set to 10 mg / m ³ and the hardness was set to 20, the siloxane generation amount was 35 μg / In Comparative Examples 1 to 3 in which the volatile component content (volatile component extraction amount) and hardness exceeded the range of the examples, the siloxane generation amounts were 210 g / m ³ and 118 g / m 3. A high value of 201 g / m ³ is shown.

  In the above description, the present invention is applied to a pressure roller of a fixing device that employs a heating roller method as a fixing method. However, the present invention relates to a fixing device that employs a fixing belt method as a fixing method. The present invention can be similarly applied to the fixing belt shown in FIGS.

  5 is a side view of the fixing belt, and FIG. 6 is a cross-sectional view taken along line AA of FIG. 5. As shown in FIG. 5, the fixing belt 34 is endless, and includes a driving roller 35 and a driven roller 36. And is driven to rotate in the direction indicated by the arrow by the drive roller 35. As shown in FIG. 6, this fixing belt 34 is formed by coating a polyimide rubber or an endless core material 37 made of metal such as stainless steel or nickel with a thickness of about 500 μm to form a silicone rubber layer 38. Further, a fluororesin film (PFA tube) 39 is coated thereon.

Thus, the fixing belt 34 is also not covered with the fluororesin film 39 of the silicone rubber layer 38 and is exposed to the outside in the width direction (paper passing width direction) both end face portions (width b portion in FIG. 6) 38A. The volatile component content is set lower than the other parts, and the hardness is set higher than the other parts. Here, the volatile component content of the end face portion 38A of the silicone rubber layer 38 is set to 10 μg / ml or less, and the hardness is set to 20 or more.

  Further, in a fixing device that employs a fixing belt method as a fixing method, the end surface portion 38A of the silicone rubber layer 38 included in the fixing belt 34 is disposed outside the image region (non-image region), and these end surface portions 38A. The thickness t1 is set smaller than the thickness t2 of the central portion (t1 <t2).

  Accordingly, also in the illustrated fixing belt 34, the end surface portion 38A exposed to the outside without being covered with the fluororesin film 39 of the silicone rubber layer 38, that is, the end surface portion 38A in which siloxane which is a volatile organic compound has been diffused conventionally. Since the volatile component content (volatile component extraction amount) of the silicone rubber constituting the rubber is set to 10 μg / ml or less and the hardness is set to 20 or more, the silicone rubber elastic body can be suppressed while suppressing the siloxane emission to the outside of the fixing belt 34. Therefore, the durability and the durability of the fixing belt 34 can be improved. In addition, in the fixing belt 34 and the fixing device including the same, the same effects as those obtained in the pressure roller 22 and the fixing device 18 including the same can be obtained.

  In the above, the present invention has been described with respect to a monochrome laser printer, a fixing device provided in the monochrome laser printer, and a fixing member such as a pressure roller and a fixing belt used in the fixing device. Regardless of whether it is a color leather printer or monochrome / color, other image forming apparatuses such as copiers and multi-function machines, fixing devices provided therein, and fixing such as pressure rollers and fixing belts used in the fixing devices Of course, the present invention can be similarly applied to members.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1A Image forming apparatus main body 2 Image forming part 3 Paper storage part 4 Photosensitive drum 5 Charging device 6 Developing device 7 Transfer roller 8 Cleaning device 9 Toner hopper 10 Laser scanner unit (LSU)
DESCRIPTION OF SYMBOLS 11, 12 Paper feed cassette 13 Pick roller 14 Feed roller 15 Retard roller 16 Paper discharge tray 17 Registration roller 18 Fixing device 19 Conveyance roller 20 Paper discharge roller 21 Fixing roller 22 Pressure roller (fixing member)
23 Fixing heater 24 Fixing roller core metal 25 Fixing roller fluoropolymer 26 Pressure roller core metal (core material)
27 Silicone rubber layer of pressure roller 27A End surface part of silicone rubber layer 27a Liquid silicone rubber with lower volatile component content and higher hardness 27b Liquid silicone rubber with higher volatile component content and lower hardness 28 Pressure Roller fluororesin film 30 Mold 31 Cylindrical mold 32 Upper mold 32a Upper mold inlet 33 Lower mold 34 Fixing belt (fixing member)
35 Driving Roller 36 Followed Roller 37 Core Material 38 Silicone Rubber Layer 38A End Surface Portion of Silicone Rubber Layer 39 Fluororesin Film of Fixing Belt S1 First Conveying Path S2 Second Conveying Path

Claims (7)

In a fixing member formed by forming a silicone rubber layer on a core material and coating the outer surface of the silicone rubber layer with a fluororesin film,
A fixing member characterized in that an end face portion exposed to the outside without being covered with the fluororesin film of the silicone rubber layer is made of silicone rubber having a lower volatile component content and higher hardness than other portions.   The fixing member according to claim 1, wherein a volatile component content (volatile component extraction amount) of the silicone rubber constituting the end surface portion of the silicone rubber layer is set to 10 μg / ml or less and a hardness is set to 20 or more. A method for producing a fixing member comprising: forming a silicone rubber layer on a core material; and coating the outer surface of the silicone rubber layer with a fluororesin film,
Two types of silicone rubbers having different volatile component contents and hardness are prepared, and the space between the core material and the fluororesin film of the vertical mold in which the core material and the fluororesin film are inserted and set in advance is provided. The liquid silicone rubber having a lower volatile component content and higher hardness is poured by a predetermined height, and the liquid silicone rubber having a lower volatile component content and lower hardness is poured thereon by a predetermined height. Further, a liquid silicone rubber having a lower volatile component content and a higher hardness is poured thereon by a predetermined height, and then vulcanized while maintaining that state.   A fixing device comprising the fixing member according to claim 1 or 2 or the fixing member manufactured by the manufacturing method according to claim 3.   The fixing device according to claim 4, wherein an end surface portion of the silicone rubber layer included in the fixing member is disposed outside the image area.   6. The fixing device according to claim 4, wherein an outer diameter or a thickness of an end surface portion of the silicone rubber layer included in the fixing member is set smaller than an outer diameter or a thickness of a central portion. An image forming apparatus comprising the fixing device according to claim 4.

Images